Bundles and kits on Shopify: planning component demand

Bundles are good for average order value and terrible for spreadsheets. A gift set that sells five a day doesn't appear in your shampoo sales, but it empties your shampoo shelf just the same. If you plan components from their own sales alone, you'll under-order the things your bundles are made of, and you'll find out when a bestselling set goes out of stock because one ingredient ran out.

Key takeaways

• Component demand = sales of the component on its own + sales of every bundle containing it × the quantity per bundle.
• Bundles can easily account for a large share of a component's demand. Plan on total demand, not standalone sales.
• A virtual bundle's availability is limited by its scarcest component, and that stock is shared with every other product that uses it.
• Pre-assembled kits have their own stock and need an assembly plan as well as a component plan.
• Mix-and-match bundles need historical choice shares to plan the components.

Three kinds of bundle

The planning depends on how the bundle exists physically.

Virtual bundles. Sold as one product but picked from component stock when the order ships. There's no bundle stock as such; availability depends on the components. Shopify's own Bundles app and many third-party apps work this way.

Pre-assembled kits. Built ahead of time and stored as their own SKU, like a boxed gift set. The kit has stock; building it consumes components.

Multipacks. The same product sold in a pack of 2, 3 or 6. Planning-wise it's a bundle with one component and a quantity greater than one.

Calculating component demand

Take a hair-care brand with three products and three bundles:

• Shampoo sells 10 a day on its own.
• Conditioner sells 6 a day on its own.
• Hair mask sells 3 a day on its own.
• Wash Duo (1 shampoo + 1 conditioner) sells 4 a day.
• Gift Set (1 shampoo + 1 conditioner + 1 mask) sells 2 a day.
• Shampoo 3-pack (3 shampoo) sells 1 a day.

Now add it up per component:

Shampoo's standalone sales are 10 a day, but its real demand is 19. Bundles account for 19 − 10 = 9 units a day, or 9 ÷ 19 ≈ 47% of shampoo demand.

The planning difference is large. With a 30-day lead time, planning on standalone sales means buying for 30 × 10 = 300 units of lead-time demand. The real figure is 30 × 19 = 570. You'd be 270 units short before safety stock even enters the picture.

Bundle availability

For a virtual bundle, the number you can sell is limited by the scarcest component:

bundle availability = lowest of (component stock ÷ quantity per bundle), rounded down

With 120 shampoo, 45 conditioner and 30 masks on hand, the Gift Set's availability is the lowest of 120 ÷ 1, 45 ÷ 1 and 30 ÷ 1, which is 30.

But that 30 isn't additional stock. If you sold 30 Gift Sets, you'd use 30 conditioners, leaving 45 − 30 = 15 for the Wash Duo and standalone sales combined. Every product sharing a component is competing for the same units. When you look at "stock available" across products, the numbers for bundles and components overlap, so never add them together to get a total.

It also means the bottleneck component sets the pace. Here, masks run out first, and when they do, the Gift Set disappears from sale even though you still have shampoo and conditioner. Your stockout report might show a mask stockout; the lost sales include every Gift Set you couldn't sell.

Pre-assembled kits

Kits add a step: you plan finished kits, and the kit plan drives component demand.

Suppose a boxed gift set sells 2 a day, you build in batches of 50, and kits take a day to assemble. Each batch consumes 50 shampoo, 50 conditioner, 50 masks and 50 gift boxes. So the gift box, which nobody ever buys on its own, is a component with real demand of 2 a day and needs its own reorder point. Packaging like this is easy to forget precisely because it never appears in sales reports.

Two rules for kits:

• Plan kit stock like a finished product, with its own cover target.
• Reserve components for the next build, so standalone sales don't consume the units you need for kits.

Mix-and-match bundles

"Choose any 3 flavours" bundles are harder because the components aren't fixed. Use the historical share of each choice.

Say a pick-3 box sells 50 a day, so 50 × 3 = 150 flavour units a day, and customers have historically chosen flavours in these shares: A 40%, B 30%, C 20%, D 10%. Component demand from the box is:

• A: 150 × 0.40 = 60 a day
• B: 150 × 0.30 = 45 a day
• C: 150 × 0.20 = 30 a day
• D: 150 × 0.10 = 15 a day

That's 60 + 45 + 30 + 15 = 150, as it should be. Add standalone sales of each flavour on top, and refresh the shares regularly, because customer preferences shift, especially after you launch a new flavour.

Promotions hit components too

If you're promoting a bundle, the promotion lifts every component. Doubling Wash Duo sales from 4 to 8 a day adds 4 shampoo and 4 conditioner a day. Shampoo goes from 19 to 23 a day: an increase of 4 ÷ 19 ≈ 21% that nobody on the shampoo side may know about. Plan promotions at the bundle level and push the uplift through to components.

Check bundle margins at component level

A bundle is a discount on its components, so check what you're giving away. If shampoo and conditioner each sell for $24 on their own, buying both costs $48. If the Wash Duo is priced at $40, the customer saves $48 − $40 = $8, a discount of 8 ÷ 48 ≈ 16.7% on both products.

That's fine if the bundle brings in orders you wouldn't otherwise get. It's less fine if most Wash Duo buyers would have bought both products anyway, or if the bundle is quietly using up conditioner that you're short of. When a component is scarce, consider pausing the bundles that use it before the component's own listing sells out: the standalone product usually earns more per unit.

Retiring a bundle

When a bundle is discontinued, its share of component demand disappears. If the Wash Duo stops, shampoo demand drops from 19 to 15 a day unless those customers switch to buying the products separately. Update the plan the day you retire it, otherwise components keep being reordered for a bundle that no longer exists.

Common mistakes

• Forecasting components from standalone sales only. The most common and most expensive error.
• Double-counting stock. Adding bundle availability to component stock overstates what you have.
• Ignoring packaging. Gift boxes, inserts and tissue are components with lead times and minimums.
• Discontinuing a component without checking bundles. Removing a product can quietly kill several bundles.
• Measuring margin on the bundle only. Check which components you're effectively discounting.

In Stokrio

Stokrio counts bundle sales as demand for each component, so component forecasts and reorder suggestions include what bundles consume. The inventory reports include a bundle component report, and each product page in the product catalogue shows the bundles and bills of materials it belongs to. For brands that assemble their own products, bundle sales also flow into raw-material planning.